Prostaglandins (PGs) are a family of acidic lipids which possess diverse physiological functions in tissues. They are believed to be ubiquitous. However, past investigations have failed to identify the products of arachidonic acid metabolism in lens. In our laboratories, initial studies on lens arachidonic acid metabolism have provided good evidence that both PGE2 and PGF2a are synthesized by rat lens microsomes and lenses grown in culture. The experiments in this proposal will examine the qualitative and quantitative profile of PG biosynthesis in the lens to firmly establish the presence of the arachidonic acid metabolites in mammalian lenses. Following determination of the PG generating capacity, experiments will be conducted to study the relationship of the PG formation to lens development, aging and the onset of galactose induced cataractogenesis. These studies will provide insight into the exent of PG biosynthesis in lens and assess the role of the arachidonic acid cascade in lens development and pathology. It is planned to extend the relevant findings in the rat lens model to the study of human lenses. Hopefully, in the long range, human normal lens functions and transparency may be maintained by manipulation of the PG biosynthetic enzyme system.